CdSe/Zn1-X CdX S core/shell heterostructured quantum dots (QDs) with varying shell thicknesses are studied as the active material in a series of electroluminescent devices. "Giant" CdSe/Zn1-X CdX S QDs (e.g., CdSe core radius of 2 nm and Zn1-X CdX S shell thickness of 6.3 nm) demonstrate a high device efficiency (peak EQE = 7.4%) and a record-high brightness (>100 000 cd m(-2) ) of deep-red emission, along with improved device stability.

Thick inorganic shell endows colloidal nanocrystals (NCs) with enhanced photochemical stability and suppression of photoluminescence intermittency (also known as blinking). However, the progress of using thick-shell heterostructure NCs in applications has been limited, due to low photoluminescence quantum yield (PL QY  60%) at room temperature. Here, we demonstrate thick-shell NCs with CdS/CdSe/CdS seed/spherical quantum well/shell (SQW) geometry that exhibit near-unity PL QY at room temperature and suppression of blinking. In SQW NCs, the lattice mismatch is diminished between the emissive CdSe layer and the surrounding CdS layers as a result of coherent strain, which suppresses the formation of misfit defects and consequently permits ~ 100% PL QY for SQW NCs with thick CdS shell (≥ 5 nm). High PL QY of thick-shell SQW NCs are preserved even in concentrated dispersion and in film under thermal stress, which makes them promising candidates for applications in solid-state lightings and luminescent solar concentrators.

Efficient white‐light‐emitting diodes (WLEDs) have been developed using a polyfluorene‐type blue‐emitting conjugated polymer doped with green and red phosphorescent dyes. The emission spectrum of the conjugated polymer, which has a very high luminescent efficiency, shows a large spectral overlap with the absorbance of green and red iridium complexes. Also, efficient energy transfer from the conjugated polymer to the iridium complexes is observed. Poly(N‐vinyl carbazole) is used to improve the miscibility between conjugated polymer and iridium complexes because of their poor chemical compatibility and phase separation. A white emission spectrum is easily obtained by varying the contents of the three materials and controlling the phase morphology. Moreover, these WLEDs show a voltage‐independent electroluminescence owing to the threshold and driving voltage of the three materials being similar as a result of energy transfer.

White light emission was obtained from a light-emitting diode prepared from polymer/quantum dot nanocomposites consisting of poly(9,-dihexylfluorene-2,7-divinylene- m-phenylenevinylene-stat-p-phenylenevinylene) (PDHFPPV) and two kinds of CdSe nanoparticles with different particle size. Blue emission from the polymer, green emission from the  nm CdSe and red emission from the  nm CdSe, which is triggered by partial excitation energy transfer from the polymer, jointly contribute to white emission of the organic–inorganic hybrid device. Also, the blue-emitting matrix polymer makes the device preparation process simpler due to its high processability. By controlling the blend ratio, we could obtain a pure white colour from the hybrid device.

Organic thin-film transistors (OTFTs) based on pentacene semiconductor are elaborated on the plastic substrates through a four-level mask process without photolithographic patterning to yield a simple fabrication process. Octadecyltrimethoxysilane (OTMS) as an organic molecule for self-assembled monolayers is deposited on the surface of zirconium oxide dielectric layer. The effect of OTMS interlayer with gate dielectric surface modification on the field effect mobility of OTFTs has been examined and these prototype organic transistors showed excellent electrical characteristics with field effect mobility >0.66cm2∕Vs and Ion∕Ioff>10.5